30 
Transactions o f the Society. 
formed, but as far as I could ascertain, some of them ate the dead 
ants and helped to keep the place clean. It appears, however, that I 
was not the only person searching ants’ nests with the same object. 
About that time Wasmann, whose studies of the social Hymenoptera 
are well known, but who was not an acarologist, had, it appears, 
been for some time collecting Acari and Insects from ants’ nests, and 
amongst other places had actually collected at Innsbruck. He had 
sent his collection to Prof. Moniez to work out, and Moniez was doing 
so when my papers appeared. Wasmann had naturally found many of 
my species, but he had also found two or three others, and it was 
interesting to see that he had found the creatures under similar cir- 
cumstances to my own. Prof. Berlese had also been hunting ants’ 
nests, and here a still more curious circumstance occurred. One of 
my Corsican species which I had observed in the nest had a knack 
when disturbed of jumping up actively on to the broad flat head of 
the nearest ant, and sitting there calmly while the ant carried it 
away, looking exactly as if it were riding it, and in fact doing so ; 
this rendered the Acari very difficult to catch, as although with a 
glass one could keep the Gamasid in view, yet it was extremely diffi- 
cult to follow the ant amongst hundreds of others. From this habit 
I called the creature Laslaps equitans. Shortly after I had announced 
this habit, &c., but doubtless before he knew of it, Berlese also 
described a Gamasid from ants’ nests, which had a similar habit, and 
he had the same idea as mine, and actually called it equitans. Oddly 
enough the creatures, although both Gamasids, and in spite of the 
similar habitat and the similar habit, not known in any other species, 
are different creatures, and Berlese felt compelled to create a new 
genus for his. In 1892 and 1893 I continued these investiga- 
tions in Cornwall, and found other species inhabiting ants’ nests, 
most of which are still undescribed. ; but again each species of Gamasid 
confined itself to a particular sort of ant, and this I have found when 
I revisited the place after a year’s interval. Amongst my Cornish 
species collected last autumn is one greatly resembling my Corsican 
L. equitans. I cannot say yet whether it is identical. It did not 
spring up upon the ants as far as I saw, but when I put it into a 
small saucer of water with other Acari, as I usually do in collecting 
or selecting Mites, instead of struggling together in a mass with their 
legs interlocked, as Acari generally do, this species sprang on to the 
other floating Acari, with the same jumping action I had seen in the 
Corsican nests, and sat quietly on their floating bodies. During my 
stay in Cornwall last autumn I observed another case of association 
between an Acarus and another creature which seemed to me very 
interesting, and which I have not hitherto recorded ; I am not aware 
that it has hitherto been observed by any Acarologist. An ant is 
usually a short-tempered creature, and not one that other small living 
beings usually come near with impunity ; still it does seem to en- 
courage a considerable number of other minute Arthropods, such as 
Aphidae, Beetles, &c., in its nest, and therefore it may not be very 
